streaming_client.py 文件源码

def __new__(cls, **kwargs):
        """Patch for abstractmethod-like enforcement in io.IOBase grandchildren."""
        if (
                not (hasattr(cls, '_read_bytes') and callable(cls._read_bytes))
                or not (hasattr(cls, '_prep_message') and callable(cls._read_bytes))
                or not hasattr(cls, '_config_class')
        ):
            raise TypeError("Can't instantiate abstract class {}".format(cls.__name__))

        instance = super(_EncryptionStream, cls).__new__(cls)

        config = kwargs.pop('config', None)
        if not isinstance(config, instance._config_class):  # pylint: disable=protected-access
            config = instance._config_class(**kwargs)  # pylint: disable=protected-access
        instance.config = config

        instance.bytes_read = 0
        instance.output_buffer = b''
        instance._message_prepped = False  # pylint: disable=protected-access
        instance.source_stream = instance.config.source
        instance._stream_length = instance.config.source_length  # pylint: disable=protected-access

        return instance